Reservoir marking instruments



Oct. 27, 1964 D. .1. SILVER RESERVOIR MARKING INSTRUMENTS 2 Sheets-Sheet1 Filed March 8. 1963 4 1V ilnnliutvulu llillla II M 4. r Ila/Ill!!!Oct. 27, 1964 D. J. SILVER RESERVOIR MARKING INSTRUMENTS 2 Sheets-Sheet2 Filed March 8, 1963 mmi smm

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United States Patent 3,153,304 RESERVOIR MARKING INSTRUMENTS DerrickJohn Silver, Letchworth, England, assignor to Mentmore Manufacturing Co.Limited, Stevenage, England, a company of Great Britain Filed Mar. 8,1963, Ser. No. 263,992 Claims priority, application Great Britain, Mar.1962, 9,216/ 62 14 Claims. (Cl. 15569) This invention relates toreservoir marking instruments of the type (hereinafter referred to asthe type specified) comprising a barrel or reservoir adapted to containa supply of a marking liquid, such as ink, a writing tip or markingelement (which may be composed of felt or similar material) mountedslidably in one end of the barrel and a valve disposed within the barreladjacent to the writing tip so that it normally shuts off the reservoirfrom the writing tip but can be actuated by applying pressure to thistip to permit marking liquid to flow to the tip from the reservoir.

Instruments of this type have generally had valves which are relativelycomplicated and expensive, both to manufacture and assemble, and requirethe provision of a barrel of somewhat larger external diameter than astandard size of fountain pen. The valve also has generally included aspring which is in contact with the marking liquid and when the latter,as is desirable in the case of marking instruments intended for use bychildren, comprises an aqueous vehicle and non-toxic colouring agents,the spring is liable to rapid deterioration with a consequent earlyfailure of the instrument.

The present invention provides improved instruments of the typespecified embodying valve arrangements of simple and cheap constructionwhich enable the production of instruments with suitably small externaldiameters for convenient use by children.

Accordingly this invention consists in a reservoir writing instrument ofthe type specified in which the valve comprises a resilient and elasticnon-metallic body having a part thereof held against displacementinwardly of the reservoir and another part thereof normally bearingagainst a valve seat but separable therefrom by a temporary deformationof the body produced by movement of the writing tip inwardly of thereservoir.

Some examples of marking instruments in accordance with the inventionwill now be described with reference to the accompanying drawings,wherein:

FIG. 1 is an elevational view of a pencil-like instrument with itspoint-protecting cap in place thereon;

FIG. 2 is a sectional elevation of the instrument with the cap removedand part of the barrel broken away, drawn to a larger scale;

FIG. 3 is a section taken on the line I[[Il1 of FIG. 2;

FIG. 4 is a section taken on the line IVIV of FIG. 2;

FIG. 5 is a section taken on the line VV of FIG. 2;

FIG. 6 is a fragmentary view corresponding to the lower end of FIG. 2but showing the valve body deformed to the valve-open position;

FIG. 7 is a fragmentary sectional view similar to that of FIG. 2 butshowing an alternative construction of writing tip;

FIG. 8 is a section taken on the line VIII-VIII of FIG. 7;

FIG. 9 is a section taken on the line D(]X of FIG. 7 of a detail of thewriting tip;

FIG. 10 is an elevation of another detail of the writing tip shown inFIG. 7;

FIG. 11 is a longitudinal section of yet another form of writing tip;

FIG. 12 is a section taken on the line XIIXII of FIG. 11;

Patented Get. 27, 1954- FIG. 13 is a fragmentary sectional elevationshowing an alternative construction of marking instrument, and

FIG. 14 is a section taken on the line XIVXIV of FIG. 13.

Referring first to FIGS. 1 to 6, it will be seen that the markinginstrument comprises a tubular pencil-like holder portion or barrel 1 ofsubstantially cylindrical shape having a detachable push-on cap 2(FIG. 1) for protecting the marking tip.

The barrel (see FIG. 2) is adapted to be closed at one end by a plug 3,after it has been filled with a coloured marking liquid 4, and is formedinternally with an annular shoulder 5 near the other end at the junctionbetween the reservoir space and a cylindrical axially extending passage6 of smaller diameter than this space.

This passage 6 serves to accommodate a length of felt rod 7, of squarecross-section, which is a sliding fit at its edges in the passage and islonger than the latter. The upper end 7a of the rod is contained in aplane normal to the axis of the rod and the lower end 7b is contained ina plane inclined with respect to the first plane, for example, :to makea dihedral angle therewith of about 45.

At its upper end the rod 7 is fitted tightly into an appropriatelyshaped recess 8a formed in the lower end of a valve element 8 ofresilient and elastic material, for example, rubber, which is receivedloosely within the lower part of the reservoir space of the barrel 1 (asviewed in FIG. 2). The valve element is of circular cross-section and isformed with an axially extending cavity 812 which opens into the centralportion of the base of the recess 3a, the cavity preferably taperingsomewhat (as shown) towards its closed upper end which is spaced a shortdistance from the upper end of the valve element. This upper end is ofhemispherical shape and its central portion fits into a partsphericalrecess 9a formed centrally of the lower face of an abutment member 9which extends diametrically across the reservoir space and is a tightfit therein, preferably being cemented in place. The abutment member 9is relatively narrow (see FIG. 3) so that it leaves unobstructedpassages 10 (FIG. 3) at each side thereof for the flow of markingliquid. It will be understood that the abutment member is secured inplace after the valve element 8 has been introduced and before thereservoir space is filled with marking liquid.

The lower end of the valve element, externally of the recess 8a.therein, is a fiat annulus contained in a plane normal to the axis ofthe element and bears with some pressure upon the inner marginal area ofthe shoulder 5 within the barrel 1, the abutment member 9 being suitablydisposed to ensure this.

It will be appreciated that, in the normal position of the parts (withthe instrument held point downwards), the marking liquid 4 filled intothe reservoir space will be unable to gain access to the felt rod 7because the valve element 8 seals the lower end of the space by reasonof its engagement with the shoulder 5 within the barrel.

When the marking instrument is to be used for the application ofmarle'ng liquid to a writing surface, such as that indicated at 11 inFIG. 6, by means of the inclined writing point constituted by the lowerend 712 of the felt rod 7, the user presses this point on to the writingsurface 11 in such a way as to urge the rod 7 axially upwards into thebarrel 1 of the instrument, as shown in FIG. 6. The pressure therebyexerted upon the value element 8 causes the later to be pressed againstthe rigid abutment member 9 and therefore to be compressed axially withthe lifting of its lower end face Sc clear of the shoulder 5 Within thebarrel 1. Marking liquid then flows past this shoulder into theclearances between the fiat faces of the rod 7 and the surface of thepassage 6 in which it is accomrnodated and contacts those faces of therod. The liquid is absorbed by the felt of the rod and any excess '2 istends to collect in the clearances. Upon release of the pressure exertedon the point of the rod, the valve element 8 resumes its normal shapeand disposition so that its lower end face 80 again seals the reservoirspace from the felt rod 7.

The user may then apply the liquid absorbed in the felt rod 7 to thewriting surface (the barrel 1 being disposed in the normal writingposition relative to the surface 11 during this operation) and mayreplenish the ink in the felt rod from time to time, by repeating thepressing action referred to above.

It should be noted that the axial compression of the valve element, withthe consequent movement of part of the rod 7 into the reservoir space,causes some displacement of marking liquid from the reservoir space intothe clearances about the rod 7 and that the return of the element 8 toits normal shape not only tends to cause any sur lus liquid in theseclearances to be drawn back into the reservoir space but also causes thenecessary liquidreplacing air to pass into the reservoir space.

An additional advantage is that the axial compression of the element 8causes this to expand radially and thus restrict the flow of liquid tothe portion of the reservoir space adjacent to the shoulder 5. Excessivepressure upon the point of the rod 7 may even cause sufficient radialexpansion of the element 8 to shut off the further flow of liquid pastthe element. Hence, flooding of the passage 6 with marking liquid islargely prevented.

FIGS. 7 to 10 illustrate a different construction of marking tip, theother parts being the same as those already described in relation toFIGS. 1 to 6 and being indicated by the same reference numerals asbefore without further description here. 4

In this case, the writing tip comprises a cylindrical tube 12 somewhatlonger than the passage 6, in which it is accommodated with some radialclearance, and containing, as a tight fit, a length of felt rod 13 (seealso FIGS. 9 and 10). The tube 12 is formed from a relatively softplastics composition. Near its inner end the tube is formed with opposedrelatively large apertures 12a through which the felt rod bulges, at 13ainto contact with the surface of the passage 6. As shown, the rod 13 isformed with a diametral slit 13b extending from its inner or upper endat least to the level of the lower edges of the apertures 12a before itis inserted in the tube so that axial compression of the rod will causethe latter to bulge outwards through the apertures, the rod 13 initiallybeing somewhat longer than the tube 12. The ends of the rod are levelwith the respective ends of the tube, the upper end being contained in aplane normal to the axis of the tube and the lower end being containedin a plane making a dihedral angle of about 45 with the first plane. Atits upper 'end the tube 12 is fitted tightly into the recess 8a in thelower end of the valve element 8.

The instrument shown in FIGS. 7 to 10 functions in the same manner asthat described with reference to FIGS. 1 to 6, the marking liquidadmitted to the annular clearance between the tube 12 and the wall ofthe passage 6 contacting those portions 13a of the felt rod 13 whichbulge through the apertures 12a in the tube 12 and being absorbed by thefelt.

FIGS. 11 and 12 illustrate another form of writing tip which may be usedin place of the felt rod 7 of FIG. 2. Although it is possible to imparta sufiicient degree of stiffness to such a felt rod, without impairingits absorbency unduly, by suitably treating the felt, it is alsopossible to achieve the desired result by employing an untreated feltrod 14 (FIGS. 11 and 12) formed with an axial bore 14a in which isinserted, as a tight sliding fit, a length of wire =15. The wire, whichmay be of stainless steel or of some other rigid and non-corrodiblematerial, is substantially shorter than the felt rod 14 and has roundedends, the wire initially being fitted so that its one end is flush withthe inclined writing face of the rod. As the latter wears away duringuse of the marking instrument the wire moves up the bore 14a so that therod remains stiff to the required degree.

In FIGS. 13 and 14 there is illustrated another marking instrumentembodying a somewhat different valve element and abutment member.

The barrel 1 has a reservoir space for the marking liquid 4 and apassage 6 of smaller diameter than this space, as in the construction ofFIGS. 1 to 6, the junction between them affording the annular shoulder5. The valve element 16 is a body of an elastic non-metallic material,such as rubber, formed of cylindrical shape with a square-section recess16a in its one end and an axial cavity 16b of circular cross-sectionextending from its other end. In the recess 16a is tightly engaged theupper end of a belt writing tip. generally indicated by the numeral 17and corresponding in every respect with the writing tip 7 shown in FIGS.2 to 6.

The annular lower face 16c of the valve element 16 is pressed lightlyagainst the shoulder 5 forming the valve seat by means of an abutmentmember 18 in the form of. an angularly bent strip ofispringyhon-corrodible metal which engages the internal wall of thebarrel 1 by its transverse edges. The limbs of the member 18 areinitially spread apart somewhat more than is indicated in FIG. 13 sothat the member is placed under stress as it is forced down the space inthe barrel to bear upon the valve member, the corners of the limbsbiting into the material of the barrel so that the member 18 will belocked in its adjusted position and cannot be displaced upwardly bynormal pressures exerted upon the valve member in the use of theinstrument. As can be seen from FIG. 14 the member 13 has a maximumwidth less than the internal diameter of the barrel so that markingliquid can flow past the member quite freely.

As in the case of the instrument described with reference to FIGS. 1 to6, the delivery of marking liquid 4 from the reservoir space in thebarrel to the clearances around the writing tip 17 within the passage 6is effected by pressing the tip inwardly of the barrel to cause axialcompression of the valve member 16 with the consequent lifting of thelower face 16c of the latter clear of the valve seat 5. As before, thedeformation of the valve member 16 produced by this axial compressioncauses some radial expansion of the member which tends to restrict theflow of the marking liquid past the valve member and thus preventsexcessive delivery of liquid to the writing tip. 7

It will be appreciated that the member 16 need not be formed with thecavity 161) but may be solid at its upper end.

I claim:

1. A reservoir marking instrument comprising a barrel having a reservoirspace adapted to contain a marking liquid, a closure for said space atone end of said barrel, a passage formed at the other end of said barrelto open at one end into said space and at'the other end to theatmosphere, said passage being aligned with and of smallercross-sectional area than said space, a valve seat formed within saidbarrel adjacent to the junction between said passage and said space tosurround said one end of said passage, an abutment secured in saidreservoir space, a rod-like marking tip slidably mounted in said passagewith its one end projecting through said one end of said passage and itsother and operative endnormally projecting through said other end ofsaid passage, and an elastic non-metallic body disposed within saidspace in engagement with said one end of said tip and interposed be-"produced in marking operations, said body being compressible to agreater degree by the exertion upon said operative end of an inwardpressure in excess of said normally produced pressures to causetemporary deformation of said body sufficient to separate said partthereof fiom said valve seat to allow flow of marking liquid into saidpassage.

2. A reservoir marking instrument as claimed in claim 1, in which saidelastic body is of such a cross-sectional area relative to thecross-section of the portion of the reservoir space in which it isdisposed that said body when temporarily deformed will restrict flow ofmarking liquid past said body.

3. An instrument as claimed in claim 1, in which said marking tip is offelt.

4. An instrument as claimed in claim 1, in which said passage is ofcircular cross-section and said marking tip is of rectangularcross-section.

5. An instrument as claimed in claim 1, in which said marking tip isformed with an axial bore and a rigid element is engaged as a tightsliding fit in said bore.

6. An instrument as claimed in claim 1, in which said marking tipcomprises a tube formed with apertures near the end thereof adjacent tosaid body and a felt rod fitted within said tube with parts thereofbulging through said apertures into the space between said tube and thewall of said passage.

7. In a reservoir marking instrument comprising a tubular pencil-shapedbarrel closed at one end which provides a reservoir space for markingliquid and which is formed at the other end with a passage aic'allyaligned with and opening into said space but of smaller crosssectionalarea than the latter, the junction between said space and said passagedefining an annular valve seat and a marking tip being inwardly slidablein said passage by pressure exerted upon its operative end, an elasticnonmetallic valve body fitted Within the reservoir space in engagementwith said marking tip between the latter and a fixed abutment normallyto bear upon said valve seat, thereby preventing flow of marking liquidto said tip, and to hold said tip against inward movement under theaction of pressures normally employed in marking operations but to bedeformable away from said seat by inward movement of said tip producedby a pressure in excess of said normally employed marking pressures soas to allow flow of marking liquid to said tip.

8. A reservoir marking instrument comprising a felt marking tip, areservoir for marking liquid and a valve for permitting said liquid toflow to said tip whenever said valve is opened by inward movement ofsaid tip, said valve comprising a valve seat and a co-operating body ofelastic non-metallic material engaged with said tip and interposedbetween an abutment within said reservoir and said tip in a compressedcondition such that inward movements of said tip for opening the valvewill alone be produced by pressures in excess of those normally employedin marking operations.

9. A reservoir marking instrument comprising a barrel having a reservoirspace adapted to contain a marking liquid, a closure for said space atone end of said barrel, a passage formed at the other end of said barrelin axial alignment with but of smaller cross-sectional area than saidspace, one end of said passage being open to the atmosphere and theother end being open to said space, an annular valve seat formed at thejunction of said passage and said space, a fixed abutment extendingacross but not filling the cross-section of said reservoir space at adistance from said valve seat, a body of elastic nonmetallic materialengaged under light compression between said abutment and said valveseat normally to bear upon the latter under the action of its ownelasticity, and a felt marking tip slidably mounted in said passage withits one end attached to said elastic body and its other end normallyprojecting out of said passage, movement of said tip inwardly of saidpassage under the action of pressures normally employed in markingoperations being resisted by said elastic body so that only the exertionupon said tip of a pressure exceeding said normally employed pressurescan urge said tip inwardly of said passage to compress said body axiallyagainst said abutment and deform it away from said valve seat to allowflow of marking liquid to said tip.

10. An instrument as claimed in claim 9, in which said v elastic body isof such a cross-sectional area that the radial expansion thereofconsequent upon its axial compression will bring its outer surface overat least part of its length into liquid flow-restricting relationshipwith the wall of said reservoir space.

11. An instrument as claimed in claim 9, in which said marking tip istightly engaged in a recess formed in said elastic body.

12. An instrument as claimed in claim 9, in which said abutment is arigid element firmly engaged at its ends with the wall of said reservoirspace.

13. An instrument as claimed in claim 9, in which said abutment is aresilient element firmly engaged at its ends with the Wall of saidreservoir space under the action of its own resilience.

14. An instrument of the character described comprising a tubular barrelclosed at one end and fitted at the other end with an axially slidablefelt marking tip, an abutment secured in said barrel but not obstructingthe passage therethrough, a valve seat within the barrel adja cent tosaid tip and a co-operating elastic non-metallic valve body engagedbetween said seat and said abutment under a degree of precompressionensuring that inward axial movement of said tip capable of deformingsaid body elastically away from said seat will be produced only when apressure is exerted on said tip in excess of the pressures normallyemployed in effecting marking operations with said tip.

References Cited in the file of this patent UNITED STATES PATENTS2,762,337 Beckwith Sept. 11, 1963

8. A RESERVOIR MARKING INSTRUMENT COMPRISING A FELT MARKING TIP, ARESERVOIR FOR MARKING LIQUID AND A VALVE FOR PERMITTING SAID LIQUID TOFLOW TO SAID TIP WHENEVER SAID VALVE IS OPENED BY INWARD MOVEMENT OFSAID TIP, SAID VALVE COMPRISING A VALVE SEAT AND A CO-OPERATING BODY OFELASTIC NON-METALLIC MATERIAL ENGAGED WITH SAID TIP AND INTERPOSED